The present invention relates to an automatic chemical analyzer for quickly analyzing a plurality of specimens or items in succession.
Automatic chemical analyzer are apparatuses which are used to examine and analyze specimens, such as urine or blood, extracted from the human body or the like. In many of recently developed analyzers of this type, urine, blood or other specimens is put into a plurality of reaction tubes, and a plurality of kinds of reagents are distributed into the tubes so that the specimen reacts with the reagents. Thereafter, the absorbance or other property of the resulting solutions is measured.
In one such prior art automatic chemical analyzer, first and second reaction sections are arranged adjacent to each other. In the first reaction section, a first rotating table supports a number of reaction tubes along a circular first arrangement line. A first drive motor rotates the first table so that the tubes move intermittently along the first arrangement line. A sampling mechanism injects the speciment into the reaction tubes, while a first reagent distributing mechanism distributes a first reagent into the tubes. A washer-drier portion serves to wash and dry the tubes. In the second reaction section, a second rotating table supports a number of reaction tubes along a circular second arrangement line. A second drive motor rotates the second table so that these tubes move in synchronism with those in the first reaction section. A second reagent distributing mechanism distributes a second reagent into the tubes. A measuring system optically measures the absorbance or other property of mixtures of specimen and reagents in the tubes. The reagent tubes are transferred between the first and second reaction sections.
Constructed in this manner, the conventional apparatus has the following three problems. First, the first and second arrangement lines have only one reagent distributing station each. Therefore, the reagent distributing mechanisms are provided with distributing nozzles which are movable between the distributing stations and a reagent repository. In distributing the reagents in accordance with the purpose of mesurement, desired reagents in the repository are indexed and injected into the reaction tubes via the distributing stations. Thus, the distributaing mechanisms are complicated and the reagent indexing takes too much time for the measurement to be accomplished quickly.
Secondly, the measuring point of the measuring system is fixed at one position on the second arrangement line. Accordingly, the reaction tubes on the second line must be transported to the measuring point in every measurement. During the transport, distribution of other reagents or other processing cannot be carried out, so that a speedy measurement is impossible.
Thirdly, since the first and second reaction sections adjoin each other, the whole appartus body is inevitably bulky.
The second problem can be solved by the technique disclosed in Japanese Patent Disclosure No. 4535/83, in ehich the measuring point is moved in the direction of arrangement of reaction tubes. The first and third problems have yet to be solved.